"If you want to reflect the real world, you will mod your Devices and aircraft loads with the correct ordnance for ASW aircraft."

If your satisfied with killing subs only on the surface, that is with GP bombs, keep it as is. Note that even dive bombers had trouble enough hitting larger Japanese ships with GP bombs, let alone relatively small submarines.

It seems that this weapon, a homing torpedo which entered service in 1943, was mostly used in the Atlantic. However, it increased the chance of a hit several fold and resulted in the sinking of 37 Axis submarines (31 German. 6 Japanese) with a further damaging of 18 more (15 German, 3 Japanese): all when only 240 (total) were deployed against Axis submarines. Thus the kill rate was slightly over 15%. As one can easily observe in the animations that rate is much better the kill rate of depth charges/hedgehogs and GP bombs. The Mk 24 "mine" was called a mine as a security measure. It does not appear to be a possible load for the TBF/TBM which could carry 4 sonobuoys AND two 324 lb depth bombs besides the homing torpedo. Frankly, count yourself lucky.

This is an interesting discussion so I spent a little time looking at the historical record of successful attacks by aircraft against Japanese submarines.

General Purpose Bombs. GP bombs have contact fuses and are ineffective against submerged submarines. They have rounded aerodynamic noses which can cause ricochet off ocean surface. WWII Japanese submarine damage or kills were credited to the following Allied aircraft using GP bombs by the USN. Data does not include unsuccessful attacks by this ordnance. Note that no submerged submarines were known to have been killed by this ordnance. Also note that three of the five known hits were scored before depth charges were available to arm the attacking unit’s aircraft.

Mark 17 – type depth bombs. The Mark 17 (aka MkXVII) 350lb depth bomb appeared in early spring of 1942 followed by the 650lb Mark 29 in May 1942. These could be carried on all Allied aircraft that could carry the corresponding weight of ordnance. The first warheads (explosive charge and casing) were standard aircraft bombs with rounded noses fitted with hydrostatic fuses rather than impact ones. The original rounded heads caused some ricochet problems so flat-nose attachments were quickly produced. Later production warheads were fabricated with blunt noses. Blunt noses allowed the bomb to “dig into” the ocean surface and sink at low entry angles, improving accuracy. The kill radius for the 350lb Mark 17 was 45 feet and for the 650lb Mark 29 was 56 feet. Hydrostatic fuses were used so that the blast occurred at or near the submarine’s depth, not on the surface. By August 1943 there were 14 different models with various warheads. Depth setting were 25, 50, 75, 100 or 125 feet. Depth had to be pre-set on the ground. The Mk 17 was effective even against surfaced submarines because it would explode below the target, damaging the hull and keeping it on the surface. In the later war years radar and sonobouys increased the effectiveness of this ordnance. Note that both surfaced and submerged submarines were known to have been damaged or killed by this ordnance. WWII Japanese submarine damage or kills were credited to the following Allied aircraft using Mk 17-type depth charges by the USN. Data does not include unsuccessful attacks by this ordnance. Success rate (according to Wolf, page 104) against Axis subs was 9.5%

The Mark 24 “Fido” Homing Torpedo. The Mark 24 “Mine” was actually a homing torpedo so designated for security reasons. It was carried by TBF/TBM Avengers aboard Hunter-Killer Group escort carriers and various other ASW aircraft. It was never carried by SBD Dauntlesses nor is the Dauntless a torpedo bomber. It was deployed to the VC squadrons from mid-1943 in the Atlantic specifically to fight U-boats. It was credited with 37 U-Boat kills in the Atlantic Theater. Since it used slow speed to listen for submarine noise, it could not effectively attack fast-moving surfaced targets or surface warships. WWII Japanese submarine damage or kills were credited to the following Allied aircraft using Mk 24 FIDO torpedoes by the USN. Data does not include unsuccessful attacks by this ordnance. Radar and sonobouys increased the effectiveness of this ordnance.Note that both surfaced and submerged submarines were known to have been damaged or killed by this ordnance. Success rate (according to Wolf, page 104) against Axis subs was 32% (142 launches and 46 hits) Unit //Unit //Air ordnance//Date//Sub//Status//Area//Result VC-13//VC-13 TBM-3E with radar and sonobouys//HVAR rockets and guns; Type Mk 17depth charges then Mk 24 FIDO torpedo//16 Jul 1945//I-13//Surfaced then submerged//550 mi east of Yokosuka//Aircraft direct USS Taylor to finish off the sub with Hedgehogs VC-69 //TBF-1C Avenger with radar and sonobouys//Mk 17-type depth charges then Mk 24 FIDO torpedo//24 Jun 1944//I-52//Surfaced then submerged//1,200 mi west of Cape Verde Is//Sunk VB-109//PB4Y-1 Liberator with radar//Mk 24 FIDO torpedo//17 Jun 1944//RO-117//Submerged//SE of Tinian//Sunk VPB-16//PBM-3D Mariner with radar//Mk 24 FIDO torpedo//2 Oct 1944//I-177//Surfaced then submerged//Off Palau//Damaged by torpedo, then sunk by USS Samuel B. Miles DE 183 VC-82//TBM-1C with radar and sonobouys//Mk 24 FIDO torpedo//26 Feb 1945//I-368//Surfaced then submerged//Off Iwo Jima//Sunk VC-82//TBM-1C with radar and sonobouys//Mk 24 FIDO torpedo//26 Feb 1945//RO-43//Submerged//Off Iwo Jima//Sonar contact by USS Bannon, attack by aircraft sunk sub. VPB-142//VPB-142 PV-2 Harpoon//Type Mk 17depth charges, then Mk 24 FIDO torpedo//27 Jun 1945//I-165//Surfaced//480 miles east of Saipan//Sunk

"If you want to reflect the real world, you will mod your Devices and aircraft loads with the correct ordnance for ASW aircraft."

If your satisfied with killing subs only on the surface, that is with GP bombs, keep it as is. Note that even dive bombers had trouble enough hitting larger Japanese ships with GP bombs, let alone relatively small submarines.

So I did rethink my statement, which was correct if you want your game to reflect reality.

Data below indicates your game results are bogus for GP bombs. General Purpose Bombs. GP bombs have contact fuses and are ineffective against submerged submarines. They have rounded aerodynamic noses can also cause ricochet off ocean surface. WWII Japanese submarine damage or kills were credited to the following Allied aircraft using GP bombs by the USN. Note that no submerged submarines were known to have been killed by this ordnance. Also note that three of the five known hits were scored before depth charges were available to arm the attacking unit’s aircraft. Data does not include unsuccessful attacks by this ordnance. Unit //Unit //Air ordnance//Date//Sub//Status//Area//Result VB-6 //SBD Dauntless //GP bombs//10 Dec 1941//I-70 //Surfaced//Off Hawaii//Dauntless badly damaged sub VS-6 //SBD Dauntless//GP bombs//10 Dec 1941//I-70 //Surfaced//Off Hawaii//Dauntless again badly damaged sub Sunk by destroyer next day RCAF Sqn No. 115 //Bolingbroke//GP bombs//7 Jul 1942//RO-32//Surfaced//Off Alaska//Bolingbroke badly damaged sub. Sunk by destroyers called to scene. TF 38//TF 38 Avenger//GP bombs//18 Jul 1945//I-372//In harbor//Off Shokaku//Sunk during harbor attack VPB-111 //PB4Y-1 Liberator with radar//GP bombs and strafing by 0.50 caliber machine guns//5 Jan 1945//Kaiten (?) Midget Submarine //Surfaced//Chichi Jima//Sunk

The SBD in the original photo above appears to be carrying a Mark-17 type depth charge on ASW duty protecting surface ships.

Summary of Japanese submarine sinking by aircraft and a few sinkings assisted by by Allied aircraft. Of course no one knows how many Japanese sub attacks were detered by the presence of ASW aircraft patrols.

The SBD photo is identified by Bing as follows. Pretty neat, in Edge you can right click on the photo and it gives you the meta-data.

Summary Description A U.S. Navy Douglas SBD-5 Dauntless of bombing squadron VB-16 flies an antisubmarine patrol low over the battleship USS Washington (BB-56) enroute to the invasion of the Gilbert Islands, 12 November 1943. The ship in the background is USS Lexington (CV-16), the aircraft's home carrier. Note the depth charge below the SBD. Date 12 November 1943 Source U.S. Navy National Museum of Naval Aviation photo No. 1996.253.680 [1] Author U.S. Navy photo 80-G-204897

The following is from "US Navy Torpedoes" by Frederick J. Milford: "340 [Fido] torpedoes [were] dropped in 264 attacks of which 204 were against submarines. In 142 attacks US aircraft sank 31 submarines and damaged 15; in 62 attacks against submarines other Allies, mainly British, sank six and damaged three. Most of these submarine sinkings were German U-boats in the Atlantic, but five Japanese submarines were sunk by Fidos, one, I-52, in the Atlantic and four in the Pacific. OEG Study No. 289, 12 August 1946, is the main source for this conclusion."

Fido was first used successfully by a British B-24 Liberator defending Convoy HX 237 on 12 May 1943, sinking U-456. This was followed by a USN PBY-5A from VP 84 which sank U-640 on 14 May 1943.

Fido would have been too slow to attack the Type XXI U-boats and could be avoided by going very deep.